Certain Dark Things
by Not Enough Answers
Summary: For twelve years, Celia Sinclair has blamed her Auror brother's death on the wizarding world—more specifically, on Sirius Black. But when Black breaks out of Azkaban, Albus Dumbledore sends them both on a quest that makes the Muggle Celia realize there is much about the wizarding world—and her brother—that she does not know...
1. Perfectly Ordinary

**This is my first HP fanfic in five years, and it feels indescribably strange to be returning to the fandom. But Sirius Black has always been one of my favourite characters, and recently I was hit with the questions: What if he fell in love with a Muggle? What if a Muggle fell in love with _him?_ So, what follows are my (rather long) answers to those questions.**

 **While I love Marauders-era stories as much as the next person, I've always found post-Azkaban Sirius to be the most intriguing. This will more or less follow book canon from PoA on, although I will be taking some creative liberties because, hey, it's fanfiction, and Sirius deserves happiness.**

 **DISCLAIMER: I am a broke Canadian twenty-something, not a middle-aged British billionaire.**

* * *

 ** _"I love you as certain dark things are to be loved, in secret, between the shadow and the soul."_**

 **\- Pablo Neruda, _Sonnet XVII_**

* * *

 **5 August 1993**

The glow of the television barely illuminated the dark room, its flickering, brightly-coloured lights broadcasting a children's programme in which a group of dancing forest creatures sang the alphabet in loud, cheerful voices. A toddler with flame-red hair sat on the floor watching them, clearly enraptured, while a woman dozed on the nearby sofa, snoring lightly. The overworked air conditioner hummed loudly in the background, occasionally giving a thump of protest, but she didn't wake.

It wasn't until the door of the sitting-room was flung open, flooding the room with light, and another woman entered with her lips pursed in disapproval that she finally started awake, blinking furiously as the sudden light nearly blinded her.

"Blimey, Coll," the woman on the sofa grumbled, surreptitiously wiping the trail of drool on her chin with her sleeve. "No need to startle me like that."

Colleen paused in her act of scooping the boy up to glare at her friend, her green eyes narrowing in annoyance. "Lia, I asked you to look after Ben for ten minutes while I made dinner. You could have told me you were too tired."

Celia winced. "Sorry. I didn't mean to. Work's been crazy lately. Anyway, Ben seemed to be enjoying himself."

The red-haired woman still looked put out, but something in her expression softened. "Nesbitt's been working you overtime again, hasn't he?"

"Yeah," Celia nodded, making an involuntary face; the boy in his mother's arms giggled. "He's been asking me to cover his shifts lately. Where he is, I have no idea…"

Colleen raised her eyebrows. "You could refuse, you know. You've been working there for over a decade."

A tiny smile appeared on Celia's lips. "What, and babysit Ben instead?"

"Sure," Colleen said encouragingly. "Sean and I would pay you well. You might even learn something while you're at it."

"I learned the alphabet a while ago, thanks," Celia replied, stifling a yawn and gesturing toward the overly-excitable woodland animals. "Besides, I don't need or want to be paid to spend time with my own godson. That is, if you trust me not to fall asleep again."

Colleen frowned, unimpressed by her sarcasm. "I'm talking about children, Lia."

"Oh, God, not this again," Celia groaned, getting to her feet and making her way to the door in a desperate attempt to flee the room. "You sound like my mother."

"Well, you're not getting any younger," Colleen pointed out, ignoring the squirming toddler in her arms. "Maybe it's time for a change—find a different job, meet new people…and Nesbitt is, well, _funny."_

Celia scowled. "I _like_ where I work," she said, a bit too defensively. "I can afford a flat in London and I don't mind living on my own. What else do I need?"

Colleen looked about to list several things, but just then Ben let out a truly ear-piercing wail and his bright eyes filled with tears as his struggles to wrest himself from his mother's grip began anew. Reluctantly dropping the topic, Colleen said, "I'd better take him to bed," and disappeared upstairs, leaving Celia blessedly alone in the sitting-room.

She flopped back onto the sofa and reached for the remote, unable to stand the prancing creatures any longer. Still, it was difficult to admit that Colleen had hit a nerve, despite the same conversation occurring between them at least once a year. _We can't all marry into money and live in a detached house in Surrey,_ Celia thought mutinously as she flipped through the channels, pressing buttons with rather more force than was necessary. She felt she would go mad if she was trapped in a place like Little Whinging, with its endless rows of twisting streets and identical houses, their small patches of garden tended to by overly-nosey neighbours. Colleen was more than welcome to it.

She skipped through several programmes, including a group of stony-faced newscasters discussing an armed, highly dangerous convict who had recently escaped from prison, before finally landing on a rerun of an American sitcom she and Colleen used to watch when they were at university. By the time her friend came back downstairs, Celia had already forgotten about their disagreement.

"It's nearly seven and Sean still isn't home," Colleen fretted, peering out the curtains at the empty driveway. "I told him you were coming for dinner…"

"Don't worry about it," Celia reassured her. "The London traffic gets worse every day—" She inhaled, frowning, as an unpleasantly acrid scent reached her nose. "Is something burning?" she asked curiously.

Colleen swore loudly and hurried out of the room, Celia jumping up and following hot on her heels, down the hallway to the kitchen, where smoke was pouring out from the closed oven door. Colleen wrenched it open and waved away the smoke, coughing as she reached inside and pulled out a singed, blackened pan, in which sat the congealed burnt mess of the casserole they were going to have for dinner.

"I forgot I'd already put this in the oven," Colleen said with a scowl, grabbing the spatula next to the sink as she began to scrape the casserole bits from the sides of the pan.

Celia hid a smile behind her hand; Colleen's disastrous attempts at cooking were the stuff of legend. She patted her friend's shoulder consolingly. "Let's just get takeaway, yeah?"

* * *

Sean arrived home at the same time as the food; he didn't appear at all surprised by his wife's sheepish explanation about burning the casserole, and instead dug into his curry with a weary acceptance, pausing only to tiredly greet Celia and kiss his son's forehead. He looked absolutely exhausted; Celia empathized with him.

"Tough day?" she asked sympathetically as she took a bite of lamb slathered in sauce. She'd already had the dish twice that week, since her flat was across the street from the best curry house in London (in her opinion), but she wasn't about to tell Colleen.

Sean dragged a hand over his face in response. "Like you wouldn't believe," he groaned, his thick Irish brogue more prominent than ever. "Canary Wharf has been swarming with police for days. You'd think the bastard had been spotted there with the number of them…"

"What was his name again?" Colleen asked, glancing up from where she was attempting to feed Ben an unappealing orange paste. "The one who escaped from that prison up north. It's been all over the news for days."

"Sirius Black," Sean said with a derisive snort, shaking his head. "Bloody lunatic name, if you ask me. Some people are just born round the bend and there's nothing you can do about it."

Celia went very still, a forkful of rice halfway to her mouth. Ice flooded her veins as if someone had poured a bucket of freezing water over her head. It was all she could do to keep her voice even as she slowly lowered her fork back to her plate and said, "S—Sirius Black escaped from prison? The man who killed thirteen people? But he had a life sentence!"

Colleen and Sean exchanged a puzzled look. "What are you talking about?" Colleen asked.

Celia swallowed, her dinner suddenly churning uncomfortably in her stomach. "It was twelve years ago. The day after Hallowe'en. In broad daylight near King's Cross. They said he just stood there and laughed when he was arrested…" She trailed off when they continued to stare blankly at her.

"But that was a gas explosion," Sean told her, his expression one of utter bafflement. "Wasn't it?"

Belatedly, Celia realized that she had revealed too much in her panic. "You're right," she said hastily, nodding as fervently as she could. "It was a gas explosion. I must have gotten it confused with something else."

Sean seemed satisfied, returning to his meal, but Celia could feel Colleen's eyes still on her. She did her best to keep her gaze averted from her friend, pretending to concentrate on the food despite her utter loss of appetite and previously cheerful mood.

After dinner had thankfully ended, during which Celia had barely managed to clear half of her plate, Sean went up to bed and she was quick to use his leave-taking as an excuse for her own departure. She had to work early the next morning, she told Colleen, and it was a ten-minute walk to the station where she would catch a train back into London. Colleen was visibly suspicious of her sudden change in demeanor, but Celia was able to say her goodbyes without incident. She paused at the end of the driveway, looking back at the house and seeing Colleen silhouetted in the doorway with Ben in her arms, warm light spilling out onto the porch, and something like longing envy washed through her. But she quashed that thought before it could become too powerful and turned away, pulling the strap of her purse higher on her shoulder and clutching the plate of leftovers in her other hand.

Magnolia Crescent stretched out before her, its large, uniform houses looming on both sides. Celia set off down the dark street, avoiding the pools of light cast by the streetlamps and tilting her head up so she could see the tiny pinpricks of stars in the inky black sky. It was unusually warm, even for summer, and the air was very still. She felt almost unnerved by the silence pressing on her ears, and quickened her pace, eager to get back to her small but cozy flat where she could take a long shower and not have to acknowledge the white-hot anger boiling inside of her, anger mixed with twelve years' worth of grief and mourning. After all the people he had betrayed, all the deaths he was responsible for, Celia had at least taken some comfort in the fact that Sirius Black would be locked up for the rest of his miserable existence, rotting in a cell in Azkaban. Now she didn't even have that.

She was going to have some _very_ choice words for Nesbitt the next day—if he decided to show up, that was.

A thin trickle of sweat ran down her forehead as she turned into the alleyway that joined the crescent with Wisteria Walk, and Celia reached up to wipe it away, wishing it wasn't quite so hot. She wasn't looking forward to the ride back to London, the train sure to be every bit as humid and sticky as the air outside, filled with commuters all crammed together like sardines in a can. At least Colleen and Sean had air conditioning and didn't hesitate to take advantage of it.

Celia was so busy thinking longingly of the house she had just left that she didn't notice she wasn't alone in the alley until she sensed movement in front of her, shadows changing position, and she immediately stopped in her tracks, instantly on alert. She didn't think she would come across any trouble in such a dull suburb, but even so, her hand twitched toward the can of pepper spray sitting at the bottom of her purse—a necessity for a single woman living in the city. But she hadn't gotten very far when she was able to discern a pair of large, glowing eyes staring back at her, eyes that were decidedly not human.

 _It's just a dog,_ she told herself in relief, and began to move forward again. The circles of light from the streetlamps barely penetrated this far inside the alley, but she could see that the dog was enormous, even larger than the St Bernard her grandfather used to own, with shaggy black hair and luminous gray eyes. Her previous relief quickly dissipating, Celia moved forward warily, wondering what a stray dog was doing in Little Whinging of all places, especially one looking as wild as this did. She expected it to growl, or at least bark as she approached, but it only stayed very still, watching her as closely as she was watching it.

Pressing herself as close to the fence as possible, Celia inched past it, holding her breath, and relaxed as soon as she was in the clear, the lights of Wisteria Walk within jumping distance. Up close, the dog was much skinnier than she'd expected, its thin frame and matted fur obvious marks of neglect. It clearly wasn't being fed regularly, if at all.

Against her better judgment, Celia paused just before the lights and turned back into the alleyway, finding that the dog hadn't moved an inch. If she hadn't known better, she might have guessed it was waiting for someone—its owner, perhaps? Nevertheless, something about its malnourished state tugged at her heartstrings, and she knew she wouldn't feel like eating anytime soon, so she hesitantly held out the plate of leftovers and asked, "Do you want these?"

The dog's ears pricked up at her words, but it still didn't move. Celia's sense of curiosity only grew; it must be very well-trained. She took a step closer to it, unwrapping the covering so that the inviting smell of meat and spices wafted out. "You look like you need this more than me," she told it, as if it could possibly understand her. "I won't hurt you, I promise."

To her surprise, the dog moved forward and trotted over to her, its tail wagging. Celia placed the leftovers on the ground and straightened up as the dog attacked the food with a delighted fervour, delving into the meal as if it hadn't eaten properly in days. She wasn't sure how healthy it was for dogs to eat curry, but she figured anything was better than no food at all.

At a speed that was astonishing even for its size, the dog licked the plate clean until there wasn't a single crumb left before raising its head and giving a small whine that Celia interpreted as thanks. She reached out and scratched behind its ears, and it gently bumped her palm with a wet nose in acknowledgement, its tail now wagging furiously. Despite her current terrible mood, Celia smiled.

When she turned away, she half-expected it to follow, or perhaps hoped; she'd never had an animal of her own, and even though her flat didn't allow pets she was sure she could find a way around it, but the dog only retreated back into the shadows, returning to its silent vigil. Its eyes gleamed strangely in the half-light. "Well, goodbye, then," Celia told it, feeling stupid. "I hope you find your owner soon."

She saw it tilt its head to the side as if in consideration of her words, and she decided to take that as an affirmative. Celia headed gratefully onto the brightly-lit street again, making a mental note to ask Colleen if she knew anyone who owned a large black dog.

* * *

The bookshop was tucked away on a surprisingly quiet street corner, neighboring a hair salon and a chemist's that had both been there for as long as Celia could remember. Despite the location's relative tranquility, it was only blocks away from Piccadilly Circus and the Tube station (another aspect she appreciated, as the line took her almost directly to her flat in Hackney). Nesbitt's specialized in rare and limited-edition books, although one could usually find a copy of the latest bestseller floating around if they knew where to look. As such, the shop attracted many unusual and eccentric patrons, much of them regulars. Celia was so accustomed to the clientele that she often found herself taken aback when she encountered a customer wearing normal clothing, and would form a silent rapport with them, reveling in her own ordinariness.

But it never took long before she was reminded that to many of Nesbitt's loyal customers, _she_ was the strange one.

"I can never quite believe that Xanthus has a Muggle working _here,"_ an elderly wizard by the name of Entwhistle chuckled as Celia rang up his purchase, the third in a series of ten volumes about Common Welsh Green breeding habits in Snowdonia. "Of all the places!"

Celia said brightly, "Well, it is a Muggle store, after all. Last time I checked, us non-magic folk were generally able to read."

If she hadn't been working for Nesbitt for as long as she had, she would never have dared to speak so frankly, but the look on Entwhistle's face was worth any rebuke. She handed his encyclopedia over to him with a cheery wave and quickly ushered him out the door, waiting until his magenta robes and custard-yellow pointed hat had disappeared before she allowed her grin to turn into a smirk. It was true that the majority of Nesbitt's customers were witches and wizards, looking for out-of-print and rare editions of books that couldn't be found in Flourish and Blotts, but they had the occasional Muggle customer as well, delighted to purchase an encyclopedia on ancient runes or flesh-eating trees. Colleen had long believed it was a New Age bookshop, an opinion Celia had no interest in altering. Her friend still refused to walk through the door, and always waited for Celia to come outside first whenever they met for lunch.

Finding herself alone in the shop again—a not uncommon occurrence—Celia moved to rearrange the display window so that the reference books on the healing properties of toadstools were more prominent, and had barely straightened up when the bell hanging above the door tinkled merrily and a windswept Nesbitt hurried inside, dressed in a pair of surprisingly nondescript black robes and a gold pocket-watch.

"Xanthus!" Celia exclaimed in surprise and relief at the sight of her manager. "I thought you said you wouldn't be coming in today."

"Yes, well, circumstances have changed," Nesbitt mumbled, hardly glancing at her as he shrugged off his cloak and headed straight for the backroom. Celia followed him, frowning; the cheerful, portly wizard was rarely short-tempered with anyone, least of all her.

She lingered in the doorway, watching him rummage through the stacks of books placed in precariously towering piles throughout the small room, dust whirling crazily around the single lightbulb hanging from the ceiling. "The Ministry has you working overtime because Sirius Black escaped from Azkaban, aren't they?"

Nesbitt shot up so fast that the top of his head connected with the low-hanging lightbulb and it spun crazily on its chain, scattering the dust even further. "How did you know that?"

"It's all over the news. The _Muggle_ news," Celia said pointedly, raising a challenging eyebrow at him. "How long were you planning to keep this a secret, Xanthus?"

He seemed to deflate at her words, some flicker of guilt crossing his face. "As long as I could," he admitted, looking decidedly sheepish. "I hoped he would be caught before you learned anything about it. Celia, I know this matter is very personal to you—"

"Of course it's personal," she interjected, disliking how pragmatic he sounded. "Black is the reason my brother is dead. What, is the Ministry thinking he's going to rejoin Lord Voldemort?"

Nesbitt visibly flinched at the name, the colour rapidly draining from his face. "Don't say that name," he hissed in a strangled tone. "But…yes, that is a likely option."

Celia nodded slowly, strangely calm. Nesbitt was many things, but he wasn't a liar. If he said that Black was planning to rejoin his master and possibly assist in bringing Voldemort back to his former strength, then she believed him. His high-ranking position in the Muggle Liaison Office also made him privy to information she would never otherwise have known. The news about Sirius Black had reached Muggle ears, and that meant the wizarding community was genuinely worried about the situation.

"I want to help catch him," Celia said evenly, looking Nesbitt straight in the eye.

His eyebrows shot up into his hairline. "But...you're a _Muggle."_

"Yes, I am," she acknowledged, trying not to sound offended by his aghast tone. "But my brother wasn't."

Nesbitt sighed audibly, as if he had anticipated this argument, and turned away from her. "He was as good as one in the eyes of You-Know-Who and his supporters."

Celia started forward, moving closer to him in her eagerness to get her points across. "A Muggle-born who also happened to be an Auror!" she exclaimed. "He knew what he was doing. If Black hadn't been passing information about the—the Order of the Phoenix and the Ministry along to Voldemort, Oliver would still be alive." Seeing that Nesbitt wasn't moved by her impassioned plea, she lowered her voice and took him by the arm, speaking in a fervent whisper. "Let me help you find Black. Please."

But her heart sank as Nesbitt pulled out of her grasp, reaching up to pinch the bridge of his nose while shaking his head. "Celia, it was all I could do to convince the Minister not to put a Memory Charm on you after the first war. I don't want to risk that again."

"I don't care about Memory Charms, Xanthus! I care about—"

"Vengeance?" Nesbitt asked coolly. "Oliver would want you to be safe." He gestured to their surroundings. "Isn't that why he got you this job in the first place?"

"Well, I wouldn't know what he wanted, would I, because he's dead!" Celia snapped, feeling heat rising to her cheeks. She rarely spoke about her brother aloud anymore, and something in her chest constricted when she said his name.

Nesbitt's expression was full of pity when he replied, as if he knew exactly what she was thinking, and she hated it. "It's been twelve years," he said softly. "Perhaps it's time to—"

"Are you wondering why I'm still working here?" Celia interrupted, refusing to let him get the better of her. "You think I can't let go of the past?"

It was difficult not to remember Colleen's words to her the previous night, to recall her friend's suggestion that Celia finally move on with her life and seek employment elsewhere. And it was equally difficult to accept the fact that perhaps she was right, that perhaps some childish, unacknowledged part of Celia believed that if she continued working for Nesbitt, one day her brother would come walking through the door again, alive and whole. Maybe Colleen really _did_ know Celia better than she knew herself.

The girls had grown up in the same Oxfordshire town, going through school together and moving to London for university. But Colleen had soon married the handsome and charming investment banker, Sean, and moved out to Surrey, while Celia continued to live the same life, the same routine, she'd had for fifteen years.

Celia was so preoccupied by her train of thought that she only realized Nesbitt hadn't responded to her outburst when he gathered up a thick, leather-bound tome and tucked it under his arm, regarding her over his pince-nez glasses and clearing his throat rather awkwardly. She quickly snapped back to attention when he said, looking as if he regretted every word, "If Black isn't caught by Christmas, I'll consider speaking to Dumbledore—"

Any jubilation Celia might have felt was overshadowed by a surge of confusion at the words. "Dumbledore?" she echoed in bewilderment. "What's he got to do with this?"

Nesbitt grimaced, clearly wishing he hadn't spoken at all. "Quite a lot," he muttered, and edged past Celia to return to the main room of the shop; it was ostensibly the end of the conversation, and she understood any other questions she asked about the subject would not receive answers, no matter how insistent she was.

Still, she found it impossible not to wonder exactly what Dumbledore believed was in one of Nesbitt's books that would help them find Sirius Black.


	2. An Unexpected Visit

**I'm back! I swear I didn't mean for this second chapter to take so long, but life just…kind of got in the way, as it tends to do, and I had to iron out lots of little details when it comes to this story and what I have planned on top of that.**

 **I love and appreciate each and every review, favourite, and follow sent my way! Thank you to everyone who stuck out the inordinately long wait for this chapter. Special thanks to saltroses for always lending a willing ear to my (many) complaints, and BouncingKappa for being an excellent sounding-board and advice-giver! This chapter is a little bit heavy on the exposition side of things, but I promise that the end result will be worth it.**

* * *

 **1 September 1971**

The boy's face shone with wild, gleeful excitement as he pushed the trolley forward, on top of which sat a cage with an indignantly hooting barn owl inside. His trunk wobbled precariously as its wheels rolled over every crack on the cobblestone, but he didn't seem to notice or mind: he was too busy staring at the scene before him, at the scarlet steam engine puffing a haze of grey smoke over the platform; at the blurred shapes of students dressed in black robes saying tearful goodbyes to their families, greeting friends, and leaping onto the train; at the hooting of owls and mewling of cats and shouting and laughter. It was unlike anything he had ever seen before, and he eagerly turned around to share in the exhilaration with his parents, who were also staring around the platform with bemused enjoyment.

"I'll write every day," he promised them, and looked at the girl hanging several paces behind, her arms crossed tightly over her chest and her lower lip quavering slightly, as if she was trying to stop herself from crying. "And I'll write you too, Lia. I promise."

His sister only continued to stare at her feet, refusing to acknowledge him. She hadn't said a word all morning—to him or anyone. Leaving his trolley with their parents, Oliver went over to her and grasped her hands tightly in his own, forcing her to reluctantly glance up. "I'll tell you everything about Hogwarts," he vowed. "All my classes, the castle, Quidditch…"

Celia shook her head stubbornly. "I should be going too," she mumbled. "I should have gotten the letter. We're _twins."_

"Magic doesn't always run in families. Professor McGonagall told us that, remember?" Oliver asked, referring to the stern, dark-haired witch who had showed up quite unexpectedly at their front door over the summer. She had explained the situation in no uncertain terms to the four of them: Oliver was a wizard, due to begin his education at Hogwarts School of Witchcraft and Wizardry the following term, and would be provided with an escort to purchase his school supplies from Diagon Alley, an exclusively wizarding area of London, safely concealed from Muggle eyes—like Hogwarts itself, and even the platform they were currently standing on.

Celia continued to watch him balefully, unable to completely conceal the look of naked longing and envy in her eyes. The twins had been inseparable as children, devoid of the gender rivalries that often existed between siblings, but Oliver's acceptance into Hogwarts had driven a permanent wedge between them. In hindsight, no one had been particularly surprised, with Mr and Mrs Sinclair taking the news surprisingly well: Oliver had always been _different—_ not exceedingly so, but enough that those closest to him had noticed since he was an infant. He had always been able to run that much faster, jump that much higher, than other children, and once after throwing a spectacular temper tantrum at the age of three, all of the lights in the house had blown out at the same time, leaving Mr Sinclair, an electrician, scratching his head. Another time Celia's favourite toy rabbit had mysteriously changed colour from purple to green after a six-year-old Oliver had played with it, and just the previous year at school he had baffled the other students and quite a few teachers by somehow climbing to the very top of an ash tree on a dare and leaping to the ground without so much as a bruise.

There had never been any doubt that Oliver was special. But there was equally no doubt that Celia _wasn't._ No matter how hard she tried, she just could not manipulate the world like her brother. Learning that there was now an entire society open to him that she would never be able to take part in was devastating. Their parents, set in their ways and comfortable in the ordinary world they'd known for decades, couldn't understand why Celia was so distraught. And, perhaps most importantly, with Oliver gone, Celia would have to learn to define herself without her twin. For their entire lives, they had always been two halves of a whole, Oliver-and-Celia. Now that connection would be broken, and they would each have to forge ahead their own, very different, paths.

"I don't want you to leave," Celia finally mumbled, so quietly that Oliver had to strain to hear it. She took her hands away to furiously swipe at the tears gathering at the corners of her eyes, and her gaze landed on another family standing within earshot of their conversation.

The father was tall and regally handsome, staring coolly around the platform with a haughty expression. The mother seemed to sense Celia watching them, and her lower lip curled in disgust as she quickly turned away. "Shameful," she hissed, loud enough so that passersby in a ten-metre radius were able to hear. "Letting Muggles in here…they'll be infesting Hogwarts next." The small boy clutching onto her hand nodded eagerly at her words, fixing Celia with a passable imitation of his mother's look. The second, older boy already dressed in robes turned around to see what the commotion was about; Celia fixed him with a fierce glare, but instead of answering with one of his own he quickly glanced away, staring down at his feet, and took a step away from his family.

"Lia, listen to me," Oliver pleaded, and her attention instantly snapped back to him. His blue eyes were wide and beseeching. He had always been the more mature of the two, despite being the younger twin. "I'll be back for Christmas, and during summer holidays. It'll be just like before—"

Celia's own eyes flashed, and she stepped back from him, shaking her head. For months, she had needed to find an outlet for all of the jealousy and frustration that had been steadily building up inside her. "No," she said shortly. "It won't. Because you'll come home a wizard, doing _magic_ , and I'll be stuck as a filthy _Muggle_ forever." She spat the words out with as much contempt as an eleven-year-old could muster, but her anger was directed inward, and at the unfairness of the whole situation. She already knew about, had read about, the wizarding world's general attitude toward non-magic people: indifference at best, loathing at worst. Would they corrupt Oliver too, turn him against his own family, make him believe he was superior? She didn't think she would be able to stand that. _She_ wouldn't, if she was in his place.

Her brother's face fell, and hurt plainly flashed across his features at her rejection. Celia's heart twisted, already regretting her harsh words, but before she could tell him that she was sorry, that she hadn't meant any of it, a piercing whistle sounded from the train and the last of the students hurried to board. Oliver turned away without another word, moving to hug and kiss their parents one last time before retrieving his trolley and joining the rest of the students, his retreating figure quickly vanishing into the haze of smoke.

Celia pressed her hand to her mouth to keep from breaking out into sobs as her tears spilled over, guilt and self-loathing wracking through her in equal measures. As the train began to pull away, she searched the crowd of faces that hung out of the windows, waving and cheering, but Oliver was nowhere to be seen. She kept her eyes fixed on them while the train gathered up speed, rounded a corner, and disappeared.

In the following years, Celia never returned to Platform 9 ¾ to see her brother off to Hogwarts.

* * *

 **25 December 1993**

"Celia, dear, do you mind fetching the post?" her mother asked when Celia poked her head inside the study, not looking up from where she was elbow-deep in a pile of term papers. The red pen didn't falter in its graceful flourishes over the page she was marking.

"Sure, Mum," Celia replied easily, though she couldn't quite help feeling like a teenager again, as she always did whenever she visited her childhood home. Jane Sinclair was a professor of English literature at Oxford, and accustomed to being obeyed. Even as an adult, Celia had never openly defied her mother's orders, and wasn't about to start now—especially not on Christmas.

She pulled on her coat and wrapped a thick but stylish wool scarf around her neck, a present from Colleen, before venturing outside into the cold. It had snowed the previous night, and the garden was covered with glittering white powder, the tightly-packed snow crunching under Celia's feet as she made her way to the mailbox at the gate.

It was quiet here, but in a different way than Little Whinging. The silence was peaceful, calm: multicoloured strings of fairy lights were twinkling from the houses lining the street; half-finished snowmen stood in many of the gardens, and the smell of Christmas baking wafted from many open windows. Even the normally bustling main street was decorated for the holidays, as Celia had seen when Jane had driven her home from the train station.

She felt strangely content being back here, in her childhood house, in the village she had grown up in. Fernsworth was a tiny town on the edge of the Cotswolds, picturesque and serene, but the teenage Celia had loathed its isolation and stagnancy, escaping to London as soon as she had been accepted into university. Now, however, she discovered a newfound appreciation for the place, so far removed from the noise and commotion she was used to. Even London became too overwhelming for her sometimes.

They'd had a subdued Christmas, the three of them, just Celia and her parents, as it had been for the past twelve years, exchanging gifts under the artificial tree and making polite small talk. Brian Sinclair, ever the tradesman, had left soon after lunch to examine the shoddy electrical work in the town square's display, and Jane had retreated into her study.

They didn't talk about Oliver. They never did, anymore. His loss had left a gaping hole that time would never fill, and they were all still grieving for him in their own ways. Celia loved her parents very much, but they weren't prone to outbursts of emotion like her. Any mourning was to be done behind closed doors; she had learned that the hard way.

"Good afternoon, Miss Sinclair."

The voice was pleasant, but Celia still gasped and spun around at the sudden diversion, the stack of mail clutched tightly in her fingers and her heart pounding wildly. There was a man standing by the garden gate, a man who most certainly had not been there a moment ago. Celia had only met him once before, but she recognized him immediately.

"Professor Dumbledore!" she gasped, still in a state of shock by the headmaster's sudden appearance at her house. He looked exactly the same as he had when he'd brought her the news of Oliver's death all those years ago, with a long white beard and half-moon spectacles perched on top of his crooked nose. He was wrapped in a forest-green travelling cloak that lightly brushed the ground, though there was no trace of snow on its hem.

"Please call me Albus," he corrected her politely, a small smile quirking up the corners of his mouth. "It is unfortunate that I never had the privilege of calling you my student."

Celia quickly looked away from his piercing, light blue gaze, recovering herself as best as she could. She had never imagined or expected to see him again, not after their first meeting had been under such unfortunate circumstances. She could think of no reason why he would be here now. "Do you want to come inside?" she asked him, her eyes fixed on the front stoop of the house opposite instead of him. "My father isn't home now, but he should be back soon—"

"As it so happens, it is _you_ I wish to speak to," Dumbledore answered, a warm smile still on his face but his tone taking on a hint of seriousness. Celia warily looked back at him. "Shall we take a walk?" he offered, gesturing to the empty street before them.

She didn't see how it would be possible to refuse, so she wordlessly nodded and fell into step beside him, the mail still clutched to her chest like a shield. Dumbledore didn't immediately speak, merely clasping his hands behind his back and humming an unfamiliar tune as he looked up at the steel-gray sky. Celia was bursting with curiosity, but she waited for him to speak first.

"I trust you are well?" Dumbledore finally asked, his eyes twinkling as he regarded her in such a way that she was suddenly sure he could read her impatient thoughts. "Xanthus is very fond of you. I do believe you are his favourite employee—not that you heard it from me, of course." His silver mustache twitched in amusement, but Celia was suddenly too preoccupied to be flattered at the compliment.

 _Nesbitt!_ Of course. She had made him promise to allow her to help them if Sirius Black wasn't caught by Christmas. Celia was more than certain that Black had long fled the country, but she still jumped at the chance to aid in the search. And Nesbitt had told her outright that he was working with Dumbledore. "Did he ask you to speak with me, sir?" she inquired, trying not to let her excitement show.

"As a matter of fact, he did not," the headmaster replied, and Celia's sense of bewilderment only grew. "But I am aware you have a particular interest in the…matter I have asked him to assist me with, and I do believe you may be the _only_ one who can uncover the answers we are searching for."

Celia stopped in her tracks, frowning up at him; her breath came out in little white puffs. "I don't understand," she said, frustrated. "Sirius Black turned over information about my brother to Voldemort that allowed the Death Eaters to track him down. I want to help you find Black, but I don't know anything. Oliver never talked about his—what he did." She swallowed hard, avoiding Dumbledore's gaze as she spoke her next words. "We weren't very close." _Not since we were eleven._

Dumbledore didn't respond for a long moment, and Celia preferred not to attempt to gauge his expression. When he finally spoke again his voice was unbearably gentle. "I beg to differ, Miss Sinclair," he said lightly. "On the contrary, it was evident that you mattered to him very much. He often spoke of you, and his main priority was to keep you and your parents safe. He would not have offered you protection with Xanthus otherwise."

There was a peculiar burning sensation in Celia's eyes, and she furiously blinked away the traitorous tears. Old wounds that she had thought healed after twelve years were beginning to ache again. "With all due respect, Prof— _Albus,_ I promise that I can't give you the answers you want. I don't know anything."

Despite her best efforts, Dumbledore met her eyes again, and there was something like regret in his next words. "When I delivered the news of Oliver's death to you, I must admit I was not entirely truthful about the circumstances leading up to it."

Celia could suddenly hear her heart pounding in her ears, thudding against her ribcage. She stared up at Dumbledore, this time bravely matching his gaze. "The circumstances?" she repeated, turning the words around in her mouth as if she had never said them before. "Oliver died because he was a Muggle-born Auror! He would have been first on Voldemort's list."

"And so he was," Dumbledore agreed, inclining his head to her slightly before amending, "One of the first, at any rate. You see, Oliver was also on a mission for the Order at the time of his death. It likely precipitated Voldemort's decision to eliminate him at all costs."

Celia didn't respond; she wasn't even sure she _could_ speak. She could only watch Dumbledore blankly, hanging onto the Headmaster's every word.

"There exists an…artefact of sorts that Voldemort wished to acquire," Dumbledore explained, his tone almost musing. Celia was vaguely aware that they had begun walking again, but she was no longer paying attention to her surroundings. "Acquire, and then destroy. When Oliver learned of it, he took the task upon himself to discover its whereabouts before Voldemort could. However, as we know, there was a spy in the Order…"

"Sirius Black," Celia finished, her mouth dry, and Dumbledore nodded. "What was this artefact, then? Why did Voldemort want to destroy it?"

A small but genuine smile played at the corners of Dumbledore's mouth. "Ah, this is where the story begins to unravel, but I am reasonably confident that I have managed to separate fact from many years of conjecture. Forgive me for launching into a history lesson, but I think you will find it helpful to your understanding of the situation.

"The Black family is one of the oldest and wealthiest wizarding families in Britain, with the vast majority of its members taking a great deal of pride in their self-proclaimed entirely magical ancestry—but of course, such a thing no longer exists. Like many other pure-blood families, the Blacks possess the unfortunate habit of simply disowning any member who marries a Muggle or Muggle-born, or who is born a Squib."

Celia felt her blood begin to boil at this less-than-flattering description of the family—she guessed that many members had been at the very least sympathetic to Voldemort's cause, if not pledging their outright support. Why, then, had anyone ever suspected Sirius Black to be any different?

But Dumbledore was speaking again, and she reluctantly turned her focus back to him.

"As I am sure you can imagine, there are many tales surrounding the family, some of them more believable than others. I, myself, am quite interested in the rumoured story of one Perseus Black, whose purported existence has consistently been denied by many scholars. According to popular myth, he created an amulet that grants its wearer, if Muggle, impervious to any and all forms of magic; if witch or wizard, it renders them unable to perform magic."

Celia's head snapped up. _Immunity to magic…_ she had never heard of any such notion, nor had Oliver ever mentioned such a potentially powerful possibility. "But why would a Black create something like that?" she asked. "If they were so proud of their abilities…"

"An excellent question," Dumbledore said. "Like many others, I thought little of the rumour, believing it to be an old wives' tale, for the majority of my life. I only began to question my assumption when your brother came to me claiming that he had been told of the amulet's location by Regulus Black, Sirius's younger brother, who was soon after killed for defecting from the Death Eaters' ranks. Oliver told me that he and a group of fellow Aurors had managed to track down Regulus, who by then was on the run from Voldemort. Knowing that Oliver was a member of the Order, Regulus told him everything he knew about the amulet, and that he, as a Black, had been tasked with finding his ancestor's possession. He implored Oliver to find it before Voldemort did, refusing any offer of protection from the Ministry.

"I was admittedly skeptical when I learned of the incident, and cautioned Oliver that it may have been a deliberate ploy. But Regulus was murdered just one week later, and I decided to use my position as Headmaster to search the school's records. I was surprised to discover that Perseus Black did indeed attend Hogwarts in the early nineteenth century, and was by all accounts exceptionally gifted at Charms. Shortly after graduating, he married a Muggle named Lyra Starling, at which point all records of him mysteriously vanished. I imagine his family did not take too kindly to the match."

Celia mulled over this for a long moment. She knew that the prevailing theory was that Muggle-borns were descended from Squibs, but she had no idea whether Oliver had gotten his magic from their mother's or father's side of the family, and frankly she didn't care. Placing value on a person based entirely on their blood status was unthinkable to her. "So Perseus enchanted the amulet and gave it to Lyra for protection," she realized, and Dumbledore nodded, his eyes twinkling as if he was pleased with her.

"Precisely. Perseus may have been disowned, but his eldest son worked hard to ingratiate himself back into the family and made a respectable pure-blood marriage. Eventually he was able to reinstate his position as the new heir to the House of Black, despite his mother's ancestry. He worked hard to erase any mention of his parents, but rumours will always persist, even to this day." Dumbledore looked thoughtful. "I do believe that is how the young Lord Voldemort learned of the amulet during his time at Hogwarts. He would have seen it as a threat to him—taking away powers from wizards and placing it in the hands of Muggles instead. But the amulet's location was unknown to everyone but a select few. His research, and mine, led to only one possibility: Lyra's grave. She predeceased her husband by some years, and he buried the amulet with her, but stated its location in his own will which only a Black would be able to access—another display of his proficiency at Charms. So Voldemort worked to lure a Black into his inner circle."

"Regulus Black," Celia realized, and Dumbledore nodded.

"Voldemort instructed Regulus to retrieve the will and the amulet, but he had already turned against him. He informed Oliver of this, and after his death your brother took it upon himself to follow the clues in Perseus's will. But there was a flaw in the plan."

"Sirius Black."

"Yes," Dumbledore said, and a heavy sadness overtook his expression. "He had become a spy for Voldemort, and passed on the information about Oliver's search, leading the Death Eaters to him. I imagine Sirius felt responsible for the amulet belonging to his ancestor, which his brother had failed to retrieve. When he was sent to Azkaban, I felt it best to simply let matters lie. But now that circumstances have drastically changed…I fear he will continue his search."

Celia had listened to the speech with first puzzlement and then outright confusion, but now something like frustration began to churn in her stomach. "So this isn't about catching Black at all?" she asked, not bothering to hide the edge of annoyance in her voice. "You just want to prevent him from finding the amulet."

Dumbledore regarded her steadily. "And you."

The wholly unexpected statement caused Celia to halt her accusations and stare blankly at him. "What? I don't know anything—"

"I recently visited Lyra's grave. The amulet was gone; in its place a note from Oliver. I believe it is addressed to you." Before her incredulous eyes, Dumbledore reached into the depths of his emerald robes and presented her with a small blue square of paper, on which was written nothing more than a series of dots and dashes.

Celia took the Post-it note with a sudden, unbearable urge to laugh. It was so… _ordinary_ —nothing about Oliver had ever been ordinary. But when she glanced down at the seemingly indecipherable code, she immediately knew exactly what it said:

.-.. .. .-

"He used to call me Lia," Celia mused. Her heart was pounding so hard that she could feel it in her veins. "It's Morse Code—a Muggle invention. Our father taught us when we were children." She frowned. "How did you know this says my name?"

Dumbledore's mustache twitched. "I do admit I had to consult Hogwarts' Muggle Studies professor. She was extraordinarily helpful."

Celia raised an eyebrow. "But you think this would be enough to deter wizards?"

"Very much so, Miss Sinclair," Dumbledore told her with a nod. "Underestimating Muggles, and believing that every problem holds a magical solution, is a flaw in a great many witches and wizards—even I must admit that I have occasionally fallen prey to such ignorance myself."

Celia was silent for a long moment as she smoothed out a wrinkle in the note with her thumb. There was nothing else on it, no invisible ink, nothing except her name written in Morse code…she wracked her brain, sorting through years of memories to try to decipher why Oliver had left her the note and what he wanted her to do, but there was nothing; nothing except for frustration and the ache of long-buried wounds bubbling up to the surface again.

"I don't know what this means," she finally said, with a shrug that failed to suggest indifference. "So he re-buried the amulet, then? And you have no idea where it could be now?"

Dumbledore shook his head solemnly. "I was not even aware that Oliver had taken the amulet. I placed a considerable amount of research into finding the location of her grave without Perseus's will to guide me."

And then, suddenly, the conversation she'd had with Nesbitt back in August clicked into place. "That's why you wanted Nesbitt to collect books for you," Celia deduced. "But then why _me?"_

"That is a question you must answer for yourself, I believe," Dumbledore replied, in his usual irritatingly vague tone. Celia looked sharply at him, but there was no twinkle in his eyes now.

"Aren't you going to help me?" she challenged him. _"Can't_ you help me?"

To her disappointment, however, Dumbledore didn't take the bait; he simply watched her with something suspiciously like pity. Celia hated being pitied. "By addressing the note to you, Oliver proved that you don't need magic to effectively conceal something you wish to remain hidden. And by doing so, he ensured your safety, just as when he suggested your employment with Xanthus all those years ago. Neither Voldemort nor his Death Eaters would suspect him of using a Muggle code, or indeed placing so much trust in the hands of his sister. Even if Voldemort himself were to discover this note, you would be safe."

"Or Sirius Black, I suppose?"

"Precisely," Dumbledore said, and his pace slowed before he came to a halt in front of the Sinclairs' gate. Celia was mildly surprised that they had returned to her house so quickly. "Now, I am afraid I must return to Hogwarts before the Christmas feast," Dumbledore politely informed her. "I do so enjoy treacle tarts. Good day to you, Miss Sinclair, and good luck. I suspect we shall be seeing each other again soon enough."

He was about to leave, and Celia still didn't have the faintest idea what she was supposed to do next, what Dumbledore wanted from her, what _Oliver_ had apparently wanted from her…all she had to go on was a blue Post-it note and her name in Morse code.

"Albus, wait!" Celia called desperately as the Headmaster turned away, throwing all caution to the wind. "How do I contact you if I discover anything or—or need to ask a question?"

Dumbledore paused, and she could have sworn she saw a smile tugging at the corners of his mustache. "Why, send an owl, of course," he said, as if it was the most obvious thing in the world. At the same moment, a violent gust of wind blew down the street, sending snow scattering about in all directions and obscuring Dumbledore from view. Celia raised a hand to cover her face, but by the time the brief, unexplainable gale had calmed and she blinked the flakes out of her eyes, Dumbledore was gone, leaving her alone again.


End file.
